Effects of Charged Particle Irradiations in Reactor Pressure Vessel Steels

摘要

Nuclear fission reactor life extension from 60 to 80 years or more will require ensuring the integrity of the reactor pressure vessel (RPV). The RPV contains the fission reactor core and is irradiated with high energy neutrons. Neutrons create primary recoil atoms in the RPV material that produce displacement cascades and excess vacancies and self-interstitials. This damage, quantified by units of displacements per atom (dpa), leads to defect-solute clustering and radiation enhanced diffusion (RED), which greatly accelerates precipitation rates. The nano-scale clusters and precipitates increase yield strength by pinning dislocations, that results in a corresponding increase in the ductile to brittle transition temperature, or embrittlement.